This invention relates generally to a method of fragmenting and removing soft tissue, and, more particularly, to a method for the removal of unwanted fatty tissues that involves the use of an ultrasonic frequency vibrating probe and a multi-lumen suction and irrigation cannula.
Liposuction is a surgical procedure for altering the human form, specifically by removal of localized deposits of fat tissues that are unresponsive to diet or exercise. The procedure is also known as suction lipectomy, lipoplasty, lipolysis, suction-assisted lipoplasty, and more recently as body contour surgery or body sculpting surgery. It is most often performed by plastic surgeons, although dermatologists, gynecologists, and other surgical specialties also perform the procedure.
The procedure is typically accomplished by inserting a small cannula or metal tube through an incision in the skin, applying a suction source to the end of the cannula that remains outside of the body, and forcing the working end of the cannula forward and backward in the layer of fatty tissue. The fatty tissue is torn, crushed, or avulsed, and is then aspirated through small openings along the sides of the cannula near the tip and then through a central lumen in the cannula to a tissue canister placed in-line with the cannula and the suction source. The procedure can involve multiple incisions and many passes of the cannula in each incision to achieve the desired cosmetic effect for the patient.
The liposuction procedure can be traumatic to the patient. The mechanical disruption of the tissues can result in, among other things, bleeding, bruising, temporary numbness, or swelling. The procedure can also be physically demanding on the surgeon because of the forces required to repeatedly push the cannula through the tissue. Further, the final cosmetic result is a function of the skill of the surgeon, the patient, and the type of surgical instrumentation used in the surgery.
Recently, efforts have been made to combine ultrasonic vibrations with the liposuction cannula to improve upon the tissue discrimination capability of the liposuction cannula and to provide an instrument that removes adipose tissue faster and more uniformly than current liposuction cannulae. This procedure is commonly referred to as ultrasound-assisted lipoplasty. In a typical ultrasound-assisted lipoplasty procedure, an ultrasonically vibrating cannula is inserted through an incision in the patient""s skin and passed forward and backward through the adipose tissue layer. The ultrasonically vibrating cannula fragments the adipose tissues, which are then typically aspirated through a central lumen in the ultrasonically vibrating cannula.
Numerous patents disclose methods and apparatus for ultrasound-assisted removal of adipose tissue from the human body. U.S. Pat. No. 4,886,491 (Dec. 12, 1989) to Parisi has a method of removing fatty tissue from a patient using an ultrasonic probe to melt at least some of the fatty tissue. The method and apparatus disclosed in this patent uses an ultrasonic frequency vibrating probe that includes an aspiration channel in the probe for the purpose of aspirating fragmented tissues.
U.S. Pat. No. 5,419,761 to Narayanan (May 30, 1995) discloses an ultrasonic handpiece with a rigid tube with an axially extending lumen.
U.S. Pat. No. 5,244,458 to Takasu (Sep. 14, 1993) has an ultrasonic handpiece with a hollow cannula with a plurality of suction openings in the cannula. U.S. Pat. No. 5,236,414 (Aug. 17, 1993) also to Takasu has an ultrasonic handpiece with a tip having a tubular body and a suction passage. U.S. Pat. No. 5,514,086 (May, 1996) to Parisi has an ultrasonic handpiece with a probe and a tip on the probe with an acoustic impedance substantially greater than that of the probe. U.S. Pat. No. 5,527,273 (Jun. 18, 1996) to Manna has an ultrasonic lipectomy probe with an enlarged head on the distal end and a longitudinally extending channel in the probe.
The use of a solid ultrasonic probe followed by the use of a single lumen suction cannula is known, as disclosed in xe2x80x9cUltrasonic Assisted Lipoplasty, Technical Refinements and Clinical Evaluationsxe2x80x9d, Michele L. Zocchi, Clinics in Plastic Surgery, Volume 23, Number 4, pages 575-598, October, 1996.
Combining the ultrasonic vibration probe and the suction cannula in a single instrument has the following disadvantages. First, in order to minimize the required incision size the outside diameter of the ultrasonic/suction probe must be kept to a minimum, typically 4-5 mm. This limits the diameter of the inner suction lumen, which is typically about 2 mm. These probes are typically from 20-30 cm in length. This creates a long, small diameter suction lumen that provides poor performance for removing viscous emulsified fatty tissues. Second, fabricating these ultrasonic probes with suction lumens requires a process known as xe2x80x98gun-drillingxe2x80x99, a process which makes the probes expensive and difficult to manufacture. Third, and most importantly, the liposuction procedure is a xe2x80x9cclosed-procedurexe2x80x9d, meaning that the instruments are passed through small incisions in the skin and the functioning tip of the instrument is not under direct visualization. The skin and fatty tissues that surround the length of the ultrasonic probe create a pressure seal that prevents the flow of ambient pressure fluids such as air to the operative site. Thus the suction process is very inefficient and ineffective because the pressure at the operative site is quickly reduced to that of the suction source, eliminating any pressure differential, and causing the flow of fragmented tissue and fluid to stop, a phenomenon which appears to the operator as a xe2x80x9ccloggedxe2x80x9d instrument.
A comparison of the suction-assisted liposuction and ultrasound-assisted lipoplasty approaches with currently available surgical instruments for both procedures was recently given in Ultrasoundxe2x80x94Assisted Lipoplasty Resource Guide, published in PlasticSurgery News, a publication of The American Society of Plastic and Reconstructive Surgeons, 1997. In the article the author cites the disadvantages of the current ultrasound-assisted lipoplasty procedure compared to the suction-assisted liposuction procedure as: 1) burns of the skin are possible, 2) longer incisions are needed, 3) seromas are more common, 4) longer operating times, and 5) greater expense.
Thus there is a need for a method of removing unwanted soft tissue, particularly fatty tissues, which permits the surgeon to work more quickly by minimizing clogging of the instruments and also reduces the potential for bums or seroma formation.
In one aspect, the present invention comprises a method for removing unwanted fatty tissues from a patient by creating a small incision in the skin of the patient, inserting an infusion probe through the incision into the patient""s fatty tissues, and infusing a wetting solution into the fatty tissues. The infusion probe is removed and an ultrasonic frequency vibratory probe is inserted through the incision and into the fatty tissues of the patient. The ultrasonic probe is activated to impart ultrasonic frequency vibratory energy to the fatty tissues causing the fatty tissues to fragment. The ultrasonic frequency vibratory probe is removed and a multi-lumen suction and irrigation cannula is inserted through the incision and into the same region of fatty tissues of the patient. Suction and irrigation are provided through the multi-lumen suction and irrigation cannula to effect removal of the fragmented tissues. The multi-lumen suction and irrigation cannula is removed from the patient and the incision in the skin is closed.
In another aspect, the foregoing method further comprises simultaneously providing suction and irrigation to the multi-lumen cannula.
In another aspect, the method involves sequentially providing suction and irrigation to the multi-lumen suction and irrigation cannula.
In a further aspect, the method further comprises providing ultrasonic frequency vibratory energy in a series of profiled pulses.
In another aspect, the method further comprises emulsifying at least a portion of the fragmented fatty tissue.